<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <!-- 引入 React 核心库 -->
  <script src="../js/react.development.js"></script>
  <!-- 用于支持 React操作DOM -->
  <script src="../js/react-dom.development.js"></script>
  <!-- 用于将 jsx转为js -->
  <script src="../js/babel.min.js"></script>
</head>

<body>
  <div id="root"></div>

  <script type="text/babel">
    // 整个构造器只会调一次
    class Weather extends React.Component {
      state = { flag: true }
      // 当 state 发生变化时 一直调用的 render
      render(){
        return <h1 onClick={this.weatherChange}>今天天气真 {this.state.flag ? '炎热' : '凉爽'}</h1>
      }
      weatherChange = () => {
        this.setState({ flag: !this.state.flag })
      }
    }
    ReactDOM.render(<Weather/>, document.getElementById('root'))
  </script>
</body>

</html>